Steam trap



Sept. 11, 1-934. 5 K|EFER 1,973,259

STEAM TRAP Filed Oct. 14, 1931 INVENTOR;

BY ATTORNEYS tractible vessel or bellows.

types are the'so-ca'l-led bucket and fioat traps.

Patented Sept. 11, 1934 umra STATES P new owner.

:SZIEAM TRAP New 55014:

Application ,October "14,

"4 Claim.

' mit water of condensation and a'irto'bedrained off by gravity or-otherwise; Perhaps the most common trap now 'inuse l-forthis purpose is the type containing a valve which is thermostatically operated by means of an =expansible and con- Qther well known All of these traps, as heretoiore constructed, contain one or more movable parts which require frequent adjustment to insure eificient op- 2 eration. They also quite easily become inoperative due to leakage, corrosion, and wear.

An object of my invention is to provide a steam trap of decidedly simple mechanical construction, which is entirely devoid of all movable parts,

.525 is not subject to the usual difliculties caused by leakage, corrosion, and wear, and will continuously operate in an efficient manner with no regulation or adjustment whatever.

Essentially the invention consists in a construction adapted to utilize the unbalanced capillary forces which may be set up in a porous plate or diaphragm, to permit the passage of water but oppose the passage of vapor. Only three primary elements are necessary to accom- 3 plish these results, namely, a steam compartment,

a condensate compartment, and a porous diaphragm or plate, the latter serving to distinctly separate one compartment from the other.

The advantages of my invention will be evi- 4 dent from a description of the accompanying drawing wherein,

Fig. l is a diagrammatic cross-section illustrating the principles of my invention.

Fig. 2 is a cross-section of a device showing a modification of the invention with the porous plate in a vertical position.

As previously mentioned the essential elements of the steam trap consist of a compartment 2 which will be referred to as the steam compart- 5 ment, a condensate compartment 3, and a porous disk 4, which separates the two compartments. An inlet 5 is provided into the compartment 2, and an outlet 6 provides means for drawing off the condensate. These elements are common to both figures and are so designated by the reference 1931, Serial No. 568,815

(c1. 1e7 ros) numerals. In Fig. 1 the porous disk 4 is sup-- porteda t one end by the casing "7 and at "the other end by the vertical member -8, which pro-- vides a side chamber 9 permitting overflow of the water to the outlet 6. In both illustrations the 3" outlet 6 is so located that thecondensate side ofthe porous disk iis always covered 'with water. Figure "2 shows-a practical torm tor trap with the porous disk 4 in a vertical position, and which is made-in sections to "facilitate assembly. Heat-Lt 'insulating washers 11 separate the two parts of the casing forming the steam and condensate compartments. The "porous disk l is new in position by the tubular :olamp 1 2 :haing a flange against which the heads o'fthe threaded boltsto mpress. Such aclamp exerts uniform pressure on the marginal part of the disk 4, and access to'the bolts 14 is provided by the removable Scorer-plate 15. In the top of the steam compartment is a vent 16, and in the lower portion a blow-off 17,475

which may be used when desired to remove the water which collects below the level of the porous disk.

The principle of operation of the two devices shown is identically the same, and will perhapsugo be more clearly evident with reference to Fig. 1. When the pressure is turned on steam and water enter the compartment 2. The capillary force of the water in compartment 2 will balance that of the water in compartment 3, but the steam pres-.: sure on the water in compartment 2 is sufficient to force it through the porous disk 4. When all of the water has been removed from the steam compartment and only the vapor remains, the capillary forces from that side of the porous disk are unbalanced and the capillary pressure of the water in the condensate compartment 3 is sufiicient to prevent the steam from passing through the disk. The water passes from the condensate compartment 3, through the channel 9 to the outlet 6, which outlet, as previously explained, is located above the level of the bottom portion of the disk 4, so that this part is at all times in contact with water, and there is a continual capillary force acting upward through the disk.

The trap will function in the proper manner only so long as the steam pressure does not exceed the opposed capillary force of the water, and the working pressure permissible is dependent on the porosity and thickness of the disk 4. Thisdisk preferably consists of a carbon plate having either a lampblack or coke base, and the porosity of the disk may be quite easily controlled by varying the particular grade of carbon used. I have found for instance that a very porous grade of carbon in the form of a plate inch thick will effectively hold steam pressures up to 3 pounds per square inch. A denser plate of coke will hold pressures up to 10 pounds per square inch, and a still more dense grade of carbon has operated efiiciently on pressures up to 26 pounds per square inch. The rate at which water is discharged also varies with the porosity and thickness of the plate, as well as with its area, and it also increases with increase in steam pressure. Knowing the conditions under which the trap is to be operated it is a comparatively easy matter to select the particular grade of carbon most suitable;.

While the trap is in operation a considerable temperature gradient is maintained between the,

steam compartment and the condensate compartment. The live steam section operates at a temperature close to that of the steam, While the con-c densate portion is considerably lower in temperature. This makes it desirable to use a porous material which has a low thermal conductivity in order to minimize the condensation of steam. In this respect also carbon is especially suitable, and in the device of Fig. 2 the washers 11 further aid in avoiding loss of heat by metal conduction from the live steam side of the trap.

The invention is not limited to the use of carbon only as the separating partition between the steam and condensate compartments, as various other porous materials may function in like manner if used in this capacity. The porousdiaphragm may be mounted in a horizontal or vertical position, and many variations in the particular manner of arranging the essential elements will be evident, all of which are within the scope of my invention as defined in the appended claims.

I claim:

1. A steam trap comprising a steam compartment having an inlet port therein, a condensate compartment, a lampblack base porous carbon disk of line capillary structure forming a vertical partition between said steam and condensate compartments, and a water outlet in the upper part of said condensate compartment above the level of the carbon disk, whereby the side of the carbon disk adjacent the condensate compartment is covered with water when the trap is in operation and the capillary action within said carbon disk opposes the passage of steam therethrough.

2. A vapor trap comprising a casing consisting of two metal sections secured together, a heat insulating gasketbetween said sections, and a partition of porous material of low thermal conductivity dividing the interior of said casing into a vapor compartment and a condensate compartment.

3. A vapor trap comprising a casing consisting of two metal sections secured together, a heat insulating gasket between said sections, and a carbon disk partition of capillary structure dividing the interior of said casing into a vapor com-- partmentand a condensate compartment.

4. A steam trap comprising a casing consisting of two metal sections joined together through heat insulating gaskets, a carbon partition in a plane with said gaskets dividing the interior of said easing into a steam compartment and a condensate compartment, an inlet to said steam compartment, and an outlet in said condensate compartment so positioned as to maintain the latter continually full of liquid, whereby capillary action in the carbon partition prevents the passage or" steam therethrough.

EDWIN F. KIEFER. 

